University of Chicago physicists have discovered signals that are consistent with WIMPs — weakly-interacting massive particles — the leading candidates for dark matter. The signals were measured in a laboratory apparatus that is buried deep below the surface of the Earth in an abandoned mine in Minnesota, where layers of rock prevent cosmic rays and radiation from interfering with the experiment. Oddly enough, physicists discovered that the signal counts were higher in the summer than in the winter, but it sort of makes sense: in the summer months the Earth’s rotation is aligned with the motion of the Sun through the disk of the Milky Way, creating a net velocity through the dark matter cloud that is theorized to envelope our galaxy.
These results are not confirmation of the existence of dark matter, but they are encouraging nonetheless, especially as they are consistent with results from ten years ago that were deemed controversial at the time.
- CoGeNT Dark Matter Experiment
- Texas Cosmology Center: “Dark Matter: Seeing the Invisible”
- Dark Side of the Universe: Dark Matter, Dark Energy, and the Fate of the Cosmos by Iain Nicolson